Appropriate analysis of the four-bar linkage

Uncertainties are inherent in the fabrication and operation of mechanisms. In terms of the four-bar linkage, uncertainties in the geometric parameters result in non-exact solutions for the coupler point. A design description which accounts for bounded uncertainties is termed an appropriate design. Appropriate analysis routines are analysis routines for guaranteeing that specific requirements will be satisfied, which is applicable to mechanisms described by an appropriate design. These routines rely on interval analysis to provide reliable results and are able to handle the uncertainties present in a mechanism. An appropriate analysis routine which is able to determine the worst-case bounds of the coupler curve resulting from uncertainties is proposed. As well, routines are introduced for evaluating the classification and assembly of mechanisms with uncertainties. Examples are presented to demonstrate the coupler curves of four-bar linkages described by an appropriate design which corresponds to each linkage classification, including folding linkages. (C) 2019 Elsevier Ltd. All rights reserved.